Luxembourg : Mohamed ElBaradei, the head of the International Atomic Energy Agency (IAEA), called Thursday for a worldwide ban on nuclear weapons as Iran continued defiance over its nuclear programme.
The European Union meanwhile expressed fresh dismay at Iran's nuclear programme and demanded that Tehran cooperate with the IAEA.
Speaking at an international conference in Luxembourg, ElBaradei said governments should forge a new collective security order, which bans all nuclear weapons.
The IAEA chief said moves by all nuclear-weapon states to extend and modernize their nuclear weapon arsenals was generating a sense of cynicism among many non-nuclear-weapon countries.
ElBaradei said prospects for progress in preventing nuclear catastrophe would remain grim unless the international community began working on a new security regime.
"The solution, in my view, lies in creating an environment in which nuclear weapons are universally banned, morally abhorred, and their futility unmasked," he said.
He insisted that the IAEA should be given stronger authority to verify nations' nuclear programmes and said countries must develop a more effective approach for dealing with proliferation threats.
The IAEA chief added that nuclear material production should be brought under multinational control, so that no one country had the exclusive capability to produce material for nuclear weapons.
Warning of a looming confrontation with Iran, ElBaradei said the country appeared on track to develop nuclear weapons in the near future.
"If Iran wanted to go for nuclear weapons, it would not be before the end of this decade or the middle of next decade, in other words three to eight years," he cautioned.
The IAEA chief appealed to Tehran to suspend uranium enrichment activity as a "confidence-building measure".
But he also urged the US and European countries to do their best to engage Iran in a wide-ranging dialogue focusing on Tehran's economic and technology concerns.
Meanwhile, Iranian President Mahmoud Ahmadinejad said there was "no way" Iran would give in over the nuclear issue.
"They (West) should know that the Iranian nation has already entered the phase of nuclear enrichment at industrial level and there was no way to withdraw even one step," Ahmadinejad said in a speech in Isfahan, central Iran, carried live by the news network Khabar.
His remarks came a day after the release of a report by the IAEA that said Iran was making progress in perfecting its uranium enrichment technology while the UN nuclear watchdog's knowledge on Iran's nuclear programme was diminishing.
The UN Security Council has issued two resolutions against Iran, warning the Islamic state to either suspend uranium enrichment or face financial sanctions.
Iran's chief nuclear negotiator Ali Larijani Wednesday termed the latest IAEA report as proof that Iran's nuclear projects were of civil nature only and within framework of internationally acknowledged rights of Non-Proliferation Treaty signatories.
The European Union voiced fresh dismay at Iran's nuclear programme and demanded that Tehran cooperate with the IAEA.
The UN Security Council tightened sanctions against Iran in March after Tehran continued to defy international demands to halt uranium enrichment. A UN deadline runs out Thursday.